Oracle automatic maintenance task

An automatic maintenance task is a database maintenance operation task automatically started according to rules. For example, the system automatically collects statistics used by the query optimizer. Automatic maintenance tasks are automatically maintained by the maintenance window

An automatic maintenance task is a database maintenance operation task automatically started according to rules. For example, the system automatically collects statistics used by the query optimizer. Automatic maintenance tasks are automatically maintained by the maintenance window

Recently, we saw an error message about VKRM In the alter log, So we learned how to query it.

From Oracle 11g, each day has its own windows and each of it has been specified default resource plan. this is something new for me too. so, I think that wocould be reason for seeing VKRM process in the alert log.



SQL> select WINDOW_NAME, RESOURCE_PLAN from DBA_SCHEDULER_WINDOWS;



WINDOW_NAME RESOURCE_PLAN

------------------------------------------------------------

MONDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

TUESDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

WEDNESDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

THURSDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

FRIDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

SATURDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

SUNDAY_WINDOW DEFAULT_MAINTENANCE_PLAN

WEEKNIGHT_WINDOW

WEEKEND_WINDOW



SYS @> AppD> SELECT WINDOW_GROUP_NAME, ENABLED, NEXT_START_DATE, comments from DBA_SCHEDULER_WINDOW_GROUPS



WINDOW_GROUP_NAME ENABL NEXT_START_DATE COMMENTS

--------------------------------------------------------------------------------------------------------

MAINTENANCE_WINDOW_GROUP TRUE 14-MAR-11 10.00.00.000000 PM Window group for automatic Maintenance

ORA $ AT_WGRP_ OS TRUE 14-MAR-11 10.00.00.000000 PM auto optimizer stats collection

ORA $ AT_WGRP_SA TRUE 14-MAR-11 10.00.00.000000 PM auto space advisor

ORA $ AT_WGRP_SQ TRUE 14-MAR-11 10.00.00.000000 PM SQL tuning advisor



SQL> select client_name, status from DBA_AUTOTASK_CLIENT;



CLIENT_NAME STATUS

------------------------------------------------------------------------

Auto optimizer stats collection ENABLED

Auto space advisor ENABLED

SQL tuning advisor ENABLED



An automatic maintenance task is a database maintenance operation task automatically started according to rules. For example, the system automatically collects statistics used by the query optimizer. The automatic maintenance task runs automatically in the maintenance window. The so-called automatic maintenance window is based on the predefined interval window.